That being said, I would have agreed with you years ago.
I think it depends on the 'nits' and the environment. "pointing out a variable name that could use a more appropriate word" as the article puts it, is not a nit if you ask me. It's something that is just part of Clean Code. Now the way that you message that you found such a suboptimal variable name plays a big role I believe as does the overall culture in the company and in the PRs. It will also depend on your relationship history with the guy pointing it out and whether you've worked with him in person/close contact or not. Friends can 'play rough' easily (what to an outsider might look like you're fighting) while actually having fun with each other. The exact same behaviour/communication would seriously turn off someone you don't really know very well.
At my place for example, we collectively have a high standard on these things and it's absolutely not considered nitpicking to point out these things. You're generally grateful for them as it happens to all of us that we just use 'some name for now' while trying out an idea and we overlook one while 'cleaning up'.
In the same vein, the "boy scout rule of coding" - "Always leave the code base in a better state than what you found it in" - can either be applied in a good way or can be taken way too far. It's all about the balance. Just like in the real camp ground, sure you will pick up the trash you found in the fire pit and when you find some more trash while wandering about camp, you'll pick that up too and throw it out. But you're not gonna laboriously interrogate every square inch of the camp ground plus a two mile radius around it, are you? You'll never get anything done that way.
Overall, this makes the codebase much easier for the whole team to work on. That's why we make code standards in the first place.